In planar display devices utilizing a liquid crystal display or the like, calibration (correction of brightness, color levels, and the like) is performed by an image information detecting device.
For example, the adjustment device of a display system disclosed in Patent Document 1 includes a photometric portion that is provided facing a liquid crystal display portion, a measurement device that measures the image quality data (image information) by detecting a signal of the photometric portion, a storage device for storing predetermined ideal recorded image quality data, and a comparison device that compares the recorded image quality data and the measured image quality data that was measured and extracts the difference data, and the image quality of the liquid crystal display portion is adjusted based on the difference data that is calculated by the comparison device.
In Patent Document 1, the image information of the liquid crystal display portion is obtained by a light receiving sensor provided in the photometric portion. However, when the calibration is performed by utilizing such an image information detecting device, it is necessary to closely contact or fix the light receiving sensor to a specified position of the display surface of the liquid crystal display portion. In this regard, if a gap is formed between the image information detecting member and the display surface, the light from the surroundings is also sensed so that accurate information cannot be detected, and an accurate calibration cannot be carried out.
Specifically, as shown in FIG. 13, as an image information detecting device 50 that performs a calibration of display devices of the type disclosed in Patent Document 1, there is used one which is configured for example by an image information detecting member 52 including a light receiving sensor 52A that receives the image light emitted from the display surface 51A of the liquid crystal display device 51, a transmission cable 53 that transmits the image information detected by the image information detecting member 52, and a deadweight 54 provided in a midway of the transmission cable 53. Here, the end of the transmission cable 53 is connected to an output device (not shown in the drawing) such as a personal computer. Furthermore, the transmission cable 53 is suspended from the upper side of the liquid crystal display device 51.
In such an image information detecting device, the image information of the display surface 51A detected by the image information detecting member 52 is transmitted to the output device through the transmission cable, and analysis of the image information is performed at the output device.
Patent Document 1: Japanese Unexamined Patent Application, First Publication No. 2005-208548.